Tunable Core Size of Carbon Nanoscrolls

We study the equilibrium core radius of a carbon nanoscroll (CNS) formed from spontaneous rolling of a graphene sheet. By a balance between the elastic bending energy and the van der Waals interaction energy in the system, we derive an analytical relation between the surface energy, the bending stiffness, the interlayer spacing, the length of a graphene sheet and the core radius of the resulting CNS. This relation is then quantitatively verified by molecular dynamics simulations. Our work immediately suggests that the core size of a CNS can be actively controlled for applications such as tunable water and ion channels, molecular sensors, as well as flexible gene and drug delivery systems.